Chalk screen image projector



JURY 25, $2 E. PEQKMAN ET AL 3,332,3E7

CHALK SCREEN IMAGE PROJECTOR 5 Sheets-Sheet Filed May 19, 1965 FIG!INVENTORS: E C K M A N EUGENE F. P

ARTHUR W. CARLSON FRANK R. TORREY FI'G4 WITNESS AORNEYS JURY 25, 19%?PECKMAN ET AL 3,332,317

CHALK SCREEN IMAGE PROJECTOR 3 Sheets-Sheet 8 Filed May 19, 1965INVENTORS,

ECKMAN A HUR W. CARLSON FRANK R. TORREY EUGENE F. P

WITNESS A ORNEYS July 25. 1967 E. F. PECKMAN ET AL 3,332,317

CHALK SCREEN IMAGE PROJECTOR 3 Sheets-Sheet 5 Filed May 1.9, 1965III/l/l/l III/Ill III III! III I FIG. 8a

INVENTORS' EUGENE F PECKMAN ARTHUR W CARLSON FRANK RTORREY WITNESSATTORNEYS 3,332,317 Patented July 25, I967 face 3,332,317 CHALK SCREENIMAGE PRGJECTDR Eugene F. Peckman, Pittsburgh, Pa., Arthur W. Carlson,

Muskegon, Mich., and Frank R. Torrey, Silver Spring,

Md., assignors to E. H. Sheldon & Company, Muskegon, Miclr, acorporation of Michigan Filed May 19, 1965, Ser. No. 457,027 9 Claims.(Cl. 8824) ABSTRACT OF THE DISCLOSURE This apparatus relates to a chalkscreen image projector, and more particularly to a screen having awriting surface in combination with means for projecting images throughthe scheen so as to become visible on the outer writing surface of thescreen. The projector is housed within a cabinet and in which a door ofthe cabinet is equipped with the screen having the writing surface, andwhen the door is moved to an open position the projector is effectivefor directing an image through the screen of the door and the writingsurface thereon to permit the use of the screen as a chalk board inconnection with the projected image.

This invention relates to a chalk screen image projector, and moreparticularly to a screen having a writing surface in combination withmeans for projecting images through the screen so as to become visibleon the outer writing surface of the screen.

An object of the invention is to provide a chalk screen projectioncenter or apparatus in which a chalk board or writing surface isprovided in the form of a screen and in combination with projectionmeans for projecting images through the screen. A further object is toprovide such a screen in a cabinet with the door of the cabinetproviding the screen. A still further object is to provide incombination with the cabinet screen door, projection means housed withinthe cabinet when the door is closed but moved to operative position forprojecting images through the screen of the door when the door isopened. A further object is to provide in such apparatus means forraising and lowering the projecting means to change the position of theprojected image on the board or screen. A still further object is toprovide a compact cabinet structure in which the projection mechanism ishoused within the cabinet and in which a door of the cabinet is equippedwith a screen having a writing surface, and when the door is moved toopen position said projection apparatus is effective for directing animage through the screen of the door and the writing surface thereon topermit the use of the screen as a chalk board in connection with theprojected image, thus avoiding shadows and glare during the use of theboard and image. Other specific objects and advantages will appear asthe specification proceeds.

The invention is shown, in illustrative embodiments, by the accompanyingdrawings, in which:

FIGURE 1 is a perspective view of a cabinet having a chalk board screenin accordance with our invention; FIG. 2, a perspective view of thestructure shown in FIG. 1 with the door opened to positionimage-projecting apparatus for the projection of an image through thescreen of the door; FIG. 3, a transverse sectional view, the sectionbeing taken as indicated at line 3-3 of FIG. 1; FIG. 4, a transversesectional view, the section being taken as indicated at line 44 of FIG.1; FIG. 5, a transverse sectional view, the section being taken asindicated at line 5 of FIG. 2; FIG. 1a, a view similar to FIG. 1 butshowing a modified form of apparatus; FIG. 2a, a perspective view of thestructure shown in FIG. 1a but with the door of the cabinet opened; FIG.3a, a sectional view, the section being taken as indicated at line 3a-3aof FIG. 1a; FIG. 4a, a transverse sectional view, the section beingtaken as indicated at line 4a4a of FIG. 1a; FIG. 5a, a transversesectional view, the section being taken as indicated at line 5a-5a ofFIG. 2a; FIG. 6a, a detail sectional view, the section being taken asindi cated at line 6a-6a of FIG. 5a; FIG. 7a, a broken detail view, theview being taken as indicated at line 7a7a of FIG. 5a; FIG. 8a, a frontview in elevation on an enlarged scale of the modified cabinet structureshown in FIGURE 1a but with the front door portions of the cabinetremoved except for a portion at the top of the figure and the projectorbeing removed; FIG. 9a, an end view in elevation of the cabinet shown inFIG. 8a with the end wall removed; and FIG. 10a, a top view of thecabinet structure shown in FIG. 8a with the top panel removed.

In the structure shown in FIGS. 1 to 5 inclusive, 10 designates acabinet having side and rear walls and provided at its front with a door11 supported on hinges 12. About midway of the door, there is provided aforwardly-extending chalk receptacle 13, and above the receptacle 13 issupported a screen 14 through which an image 15 shown in dotted lines inFIG. 2 is projected. The screen 14 has its outer surface treated orroughened to provide a chalk board surface so that the screen surfacehas a blackboard for the use of chalk, crayons, or other writingmaterial.

The screen 14 may be formed of glass having a frosted front surface, orof glass provided on its outer surface with suitable plastic materialwhich provides a transparent sheet but which also may be polished ortreated to receive chalk impressions, etc. A plastic-coated glass panelnot only is useful in transmitting the image therethrough so as torender it visible on the front surface thereof, but also the frontsurface readily receives and records chalk and other Writing materials.

The door 11 may be provided at its lower portion with small doors 16 and17'to provide access to storage space in the lower portion of thecabinet for receiving transparencies, etc. In such space, an adjustableshelf 18 may be mounted as shown in FIG. 4.

Fixedly secured to the door 11 is a horizontal platform 19 whichswingsoutwardly and inwardly as the door is opened and closed. The platform 19is connected to the cabinet by a chain 20 and the chain limits theoutward swinging movement of the door 11.

A mirror or reflector 21 is carried by a backing or frame 22, and theframe is pivotally supported upon the platform 19 by the pivot rod 23.The reflector frame is anchored to the rear wall of the cabinet 10 by achain 24. A tension spring 25 is anchored at one end to the platform 19and at the other end to a lever 26 connected to the pivotally-mountedbacking or frame 22. As the door is swung outwardly to operativeposition, as shown best in FIG. 5, the pivot rod 23 coacts with thechain 24 and the spring 25 to hold the reflector 21 in position fordirecting the image upon the screen 14.

An image projector 27 is supported upon table 28, and when atransparency is placed upon it, directs the image upwardly to a lens 29carried by support arm 30. By means of the lens 29 and the reflector 21,the image is projected through the screen 14 and appears on the frontface thereof, as indicated by the numeral 15 in FIG. 2.

Any means for supporting the table 28 may be provided. In theillustration given, we provide a standard 31 having feet 32 equippedwith glider buttons 33, and upon the standard 31 is mounted a framemember 34 apertured to receive the rods 35. The rods 35 may be adjustedwithin the apertures and secured therein at the desired height by theuse of set screws or other suitable means. Secured to the frame member34 is a V-shaped support 36 having at their inner ends a slide member 37mounted within the track 38 carried by platform 19, as shown best inFIG. 5. Thus, the inner end of the V- shaped support 36 is slidablycarried within the track 38, and this support together with the pedestal31 movably carries the table 28 upon which projector 27 is mounted.

Operation In the operation of the apparatus, the projecting mechanism 27and associated parts are held within the cabinet, as shown best in FIGS.1 and 3. In this position, the screen 14 is useful as a chalk board.When, however, the door is swung open until limited by the chain 2%) andthe table 28 is drawn outwardly until the slide 37 reaches a stop at theend of the track 38, the apparatus is automatically in position forsupplementing the chalk board 14 with a projected design. When theslected transparency is placed upon the projector 27 and the projectorilluminated, the image therefrom is projected through the screen 14 soas to be visible on the :front face thereof. In the specificillustration given, a graph image is projected onto the screen, and theinstructor or person using the chalk board may then draw the other linesinsuperposed relation over the graph, as illustrated in FIG. 2. Forexample, problem constructions, graphs, coordinates, and other imagesmay be projected upon the screen, and these may be copied or extended bythe use of chalk, etc. as they appear on the screen. The screen thusbecomes an actual work station, enabling the instructor or other personto utilize in the background the projected image while he makesmodifications thereof. The user can stand next to the screen withoutcasting shadows to interfere with his own view or the views of others.

When the projector is no longer to be used, the parts may be moved toclosed position, as illustrated best in FIG. 3, the parts movingautomatically into the position shown by merely moving the projectionsupport structure inwardly and closing the door 11.

In the modification illustrated in FIGS. 1a to a inclusive, the cabinet39 has an upper door 40 which extends over the upper portion of thecabinet only. The lower doors 41 and 42 extend over a fixed portion ofthe cabinet which may contain partitions 43 useful for re?- ceivingtransparency plates, etc. Fixed to the upper door 40 is a chalkreceptacle 44, and above it a screen 45 similar to screen 14 of FIGS. 1to 5 inclusive.

Fixed to the door 40 is a platform 46 having drawer sides 47 and inwhich is mounted a slide 48. The rear end of the slide 48 is preferablyprovided with partitions 49 adapted to receive transparencies, etc.

A reflector 50 is carried by frame member 51. A chain 52 connects oneend portion of the frame to the rear side of the cabinet 39. A spring 53connects the other end of the frame 51 to a side wall of the cabinet 39.The frame 51 is pivotally mounted upon platform 46 in the manner shownbest in FIGS. 9a and 10a. A pivot strap 54 has a lower apertured endreceiving a pivot pin 55 and a similar apertured upper end receiving apivot pin 56. The pivot pin 56 connects the apertured upper end of strap54 to a pair of straps 57 and 58 which have their forward ends connectedto the door 40.

The cabinet 39 has an intermediate fixed transverse partition wall 59extending across the cabinet just below the platform 46, as shown bestin FIG. 9a, and this partition is provided with a stop member in theform of a screw 60 which engages a flange stop 61 carried by theplatform 46, as shown best in FIG. 6a, so that, when the platform 46 hasbeen swung outwardly to the operative position shown in FIG. 5a, thestops 60 and 61 limit further outward movement of the platform.

A projector 27a, similar to projector 27 hereinbefore described, iscarried by a table 62, and the transparency image is directed by lens 63upon the reflector 50. In

order to fold the table 62 compactly within the cabinet 39, we mount thetable eccentrically upon the slide member 48 and also provide mechanismfor raising and lowering the table 62. As shown best in FIG. 9a, thetable 5 62 is eccentrically mounted at 64 upon plate 65, and plate 65 isconnected by lazy tong links 65a to a lower plate 66. By means of ascrew engaging a nut connected with the plate 66 and operated by handle67, the link members are caused to raise and lower to elevate the table62. Since such lifting structure is well known, a further detaileddescription herein is believed unnecessary.

In order to limit the rotation of the table 62 upon the plate 65therebelow, we provide these members with angle stops 68, as shown bestin FIG. 7a.

In the operation of the modified structure shown in FIGS. la to 10ainclusive, the door 40 which covers the upper portion of the cabinet ismoved inwardly and outwardly. When moved outwardly to the operativeposition shown in FIG. 5a, the slide 48 is drawn outwardly, and thetable 62 is swung on the eccentric pivot 64 to the position shown inFIG. So so that the image is directed from the lens 63 upon thereflector 50 and therefrom through the screen 45. In this operation, thereflector is drawn automatically to the proper position shown in FIG.5a.

When the parts are to be moved back into the cabinet, the table 62 isrotated to the position shown in FIG. 3a and the slide 48 is movedinwardly, and then the door 49 is moved to closed position. Thereflector structure is brought automatically to the position alongsidethe rear wall of the cabinet, as shown in FIG. 3a.

While in the foregoing specification we have shown specfic structures inconsiderable detail for the purpose of illustrating embodiments of ourinvention, it will be understood that such details may be varied widelyby those skilled in the art without departing from the spirit of ourinvention.

We claim:

1. In combination with a cabinet provided with a door, said door havingas a panel thereof a translucent screen with a front chalk-receivingsurface, image projector means, reflector means associated therewith forprojecting an image through said screen from the rear thereof and Dvisible from the front thereof, and cooperating means on said door andcabinet for aligning said projector and refiector means in operativeposition when the door is opened to a predetermined position.

2. The structure of claim 1 in which means are provided for raising andlowering the projector for changing the position of the image on saidscreen.

3. The structure of claim 1 in which means are provided for moving saidprojector and reflector means into folded position within said cabinet.

4. In combination with a cabinet having a chamber in the upper portionthereof, a door closing said chamber, said door having as a panelthereof a translucent screen with a front chalk-receiving surface, imageprojector and reflector means associated with said door for projectingan image through said screen from the rear thereof and visible from thefront thereof, means for folding said projector and reflector meanscompactly within said cabinet when the door is closed, and means forswinging said projector and reflector means outwardly when said door isopened.

5. In combination, a cabinet equipped at its front with a door having atranslucent screen provided with a chalkreceiving front surface, aplatform fixed to said door, a reflector carried by said platform, meansassociated with 70 said platform for supporting a projector memberoutwardly fro-m said door when said door is opened, and means foraligning said reflector and projector means for directing an imagethrough said screen when said door is opened to operative position.

6. The structure of claim 5 in which said supporting 5 means for saidprojector is equipped with a pedestal and feet adapted to rest upon thefloor.

7. The structure of claim 6 in which said supporting means is carried bysaid platform.

8. In combination with a cabinet provided with a door having a panelthereof a translucent screen with a front chalk-receiving surface, imageprojector means and reflector means associated therewith for projectingan image through said screen from the rear thereof, a platform carriedby said door extending inwardly of said cabinet, a slide member carriedby said platform, a table for sup porting said projector meanseccentrically mounted upon said slide member, and cooperating means onsaid door and cabinet for aligning said projector and reflector means inimage-projecting position when said door is opened to a predeterminedposition.

9. The structure of claim 8 in which said slide member is provided withmeans for raising and lowering said table.

References Cited UNITED STATES PATENTS 1,242,674 1 0/1917 Fleischer352--51 1,589,349 6/ 1926 Bavsch et a1. 8824 1,787,309 12/1930 Gol-dbeck352- 243 1,840,920 1/1932 Spaulding 88-24 2,474,297 6/ 1949 Young 88 242,522,351 9/1950 Egolf 3566 3,051,040 8/1962 Davis 8824 FOREIGN PATENTS572,528 10/ 1945 Great Britain.

NORTON ANSHER, Primary Examiner. R. M. SHEER, Assistant Examiner.

1. IN COMBINATION WITH A CABINET PROVIDED WITH A DOOR, SAID DOOR HAVINGAS A PANEL THEREOF A TRANSLUCENT SCREEN WITH A FRONT CHALK-RECEIVINGSURFACE, IMAGE PROJECTOR MEANS, REFLECTOR MEANS ASSOCIATED THEREWITH FORPROJECTING AN IMAGE THROUGH SAID SCREEN FROM THE REAR THEREOF ANDVISIBLE FROM THE FRONT THEREOF, AND COOPERATING MEANS ON SAID DOOR ANDCABINET FOR ALIGNING SAID PROJECTOR AND REFLECTOR MEANS IN OPERATIVEPOSITION WHEN THE DOOR IS OPENED TO A PREDETERMINED POSITION.